Indicating device



May l, 1928.

C. H. HAPGOOD INDIGATING DEVICE Filed Nov. 10. 1923 ing a sighting index as they do in the abovenientioned patent to Mingle. It is to be understood, however, that another form ot sighting index, such, ior example, as a ribbon, may be employed in lieu ot the wires t and 7 to accomplish the saine purpose. oth wires are secured at their ends to brackets 8, preferably constructed in V shape, the bights ot' the Vshaped brackets being lixedly secured to the arms 9 through the medium oi the studs 10, the inherent resiliency in the wings oi the brackets serving to retain the wires in a continued state ot tension. The arms 9 to which the brackets 8 are. secured are pivoted upon screws 11, the axes ot which are positioned coincident with a line upon the sul-'tace ot the chart t and in paralieiisiu therewith.

Positioned parallel with the chart 4 and within the housing 5 is a shatt 12 journaled in apertures in the housing end plates 13, and iixedly positioned upon said shaft at either' end of the chart t are the lingers 1.4 which contact with depending portions 'l5 of the arms 9. Contractile springs 17 secured to the ends of the arms 9 resiliently retain the arms and fingers 1i in contact.

Fixedly secured to either extremity ot the shat't 12 exteriorly ot the housing end plates 13 are the knobs 16 to facilitate adjustment. Enough friction is set up between the shaft 12 and its journals to overcome the contractile torce ot the springs to retain the mecha nism in any adjusted position.

As has been previously stated, the axes of the screws 11 upon which are pivoted the arms 9 being coincident with an imaginary line upon the tace ot the chart, it will readily appear that it the arms 9 are partially rotated upon the screws 11 by n'ieans of the shaft 1Q and the lingers 151. that a plane passing through the wires 6 and 7 would lie rotated about this line as its axis. lVhen the eye of the observer is in this in'iaginary plane, the 'ires apparently blend into a reading index having the thickness ot one wire. and the line at coinputations Vin visual coincidence with this reading index always remains the. same. regardless ot' the position ot the arlns 9 and the consequent change in the plane of the reading and sighting wires.

It will he readily understood from the foregoing description that the index and sighting wires may be shifted to suit, the. eye ot the observer, whether he be tall or short, without causing him unnecessary inconvenience or fatigue.

The cnibodiniei'it ot my invention herein shown and described is lo he regarded as illustrative only, and it is to be understood that the invention is susceptible to variation, moditication and change within the spirit and scope o the subjoined claims.

Having described my invention, I claim:

l. In a device of the class described, in combination, a movable chart, reading and sighting indices cti-operating therewith. a pivotal support tor said reading and sight` ing indices, tht` pivotal axis ol' said .support lying in the plane of' the surface ol .said chart, and means tor adjusting said .support about its pivotal axis.

2. In a device of the class described. in combination, a movable chart, linear reading and sighting indices, resilient means tor tensioning said indices, and means l'or partially rotating said indices such that the axis ot rotation of a plane passing through said indices will be a lixed line upon tlie'chart,

3. In a device of the class described, in con'ibination, a movable cylindrical chart. reading and sighting indices lying parallel with the axis oi' said chart, resilient means for tensioning said indices, means vl'or supporting said tensioning means, and manually-operated means for partially rotating said supporting means, includingr .said in dices, the axis of rotation ot' a plane passing through the reading and sighting indices bei ing a fixed line upon the face ofthe chart.

At. In a device ot the class described, in conibination, a housing, a cylindrical chart rotatably mounted in said housing', reading;r and sighting indices positioned parallel with the axis ot' said chart, a support tor said in' dices. and means extending to the exterior o t' said housing ttor adjusting said support.

5. ln a device oil the class desrgribed. in combination. a relatively i'i'irnablt;l chart and sighting index, a pivotal support tor ,said index, the pivotal axis ot said support lyinLr in the plane ot said chart and coinciding with a line to be indicated by said index` and means for adjusting said support about its pivotal axis. 

